By Chuck Mikolajczak
NEW YORK (Reuters) - NYSE Arca has suspended trading in eight symbols for the balance of the trading day because of a technical issue, including Amazon.com and both classes of Alphabet Inc shares, according to an alert from the exchange.
The alert stated that all orders have been canceled back to customers and a spokeswoman for the exchange confirmed it was not an April Fool's Day prank.
The NYSE said the problem was not a system or trading issue but a market data issue affecting a small subset of stocks that it was working to rectify.
Trading volume near midday on Amazon was about 1.2 million, 28 percent of its 10-day average. Alphabet Class A volume of roughly 495,000 shares was 29 percent of its 10-day average while Class C volume of nearly 556,000 shares was about 31 percent of the 10-day average.
Market participants have dealt with trouble trading issues at different exchanges in recent years, including a three-hour outage by Nasdaq in August 2013.
"In this case, the competitive U.S. exchange landscape is a benefit, allowing for securities to continue to trade while one operator may be down for technical reasons," said Ryan Larson, head of U.S. equity trading at RBC Global Asset Management in Chicago.
"At the same time, the competitive environment in both lit and dark venues continues to pose significant fragmentation issues regarding meaningful liquidity."
The NYSE on Feb. 1 rolled out a new trading platform called Pillar, but it was not known if issues with the new platform had spurred the trading suspension.
Other affected stocks included AutoZone Inc, Intuitive Surgical and Markel Corp.
Joe Christinat, a spokesman for Nasdaq, said "all our systems are operating normally" and the stocks could be traded on the Nasdaq regardless of issues at another exchange.
(Editing by Bernadette Baum and Steve Orlofsky)